Encephalitis during first year of SARS-COV-2 pandemic– first results of the European ENCOVID registry

Background and aims: Objective: Several preclinical and clinical investigations have argued for nervous system involvement in SARS-CoV-2 infection. No data about clinical, imaging and biomarkers presentations as well as long-term outcomes are available for SARS-CoV-2 encephalitis in comparison with infectious and autoimmune encephalitis. Methods: The ENCOVID European registry included patients with probable or definite diagnosis of encephalitis with and without SARS-CoV-2 infection admitted for hospitalization in the European recruiting centers between February 1st 2020 and March 30th, 2021. Each patient underwent a standardized assessment including full infectious screening, CSF, EEG, MRI data. Clinical presentation and laboratory markers, severity of COVID-19 disease, response to treatment and outcomes were recorded. Results: Results – Out of 155 cases screened, forty-five cases of encephalitis positive for SARS-CoV-2 infection and 63 without COVID-19 with full available data were included. SARS-CoV-2 encephalitis exhibited common presentation with aphasia and dysarthria compared to non-COVID- encephalitis and exhibited higher prevalence of patients with normal MRI but mild hyperproteinorracchia/pleocytosis. Most SARS-CoV-2 cases appeared during the onset of COVID-19 and exhibited different response to treatment and long-term outcomes compared to non COVID encephalitis. Conclusions: Conclusions –The registry identified a wide spectrum of encephalitis associated with COVID19 infection, with clinical characteristics and course different from classical infectious and autoimmune encephalitis. Biomarkers studies are warranted in order to evaluate the specific inflammatory pathways associated with SARS-Cov-2 encephalitis.